okmatey
10 mW
Super,thanks so much its starting to make sense now, any suggestions on a second controller ??
NEWBIE, Land rover electric bike project
- Thread starter okmatey
- Start date
okmatey
10 mW
This is good stuff,so if you would suggest a second controller what would you choose? Or should I say what's the cheapest option ?
Also because the other controller has a display cable what display would you consider ?
A Frankenrunner if its still available, or a Phaserunner would be absolutely awesome.
.....Oh you probably meant cheap, most likely, better buy one that lots of people have bought from and has had great success with, better buy one that has good documentation, better buy one that has a picture of the wires and their names, might be the proper picture but might not be, which is why one would buy one from a place that others have purchased from frequently and has had little problems with in terms of returning or receiving damaged items or recieving the wrong item. You'd want a known entity I'd believe, a place that sells lots of quantity of product, a place that sells only ebike stuff. PSW Power is good for your displays and such, Greentime is good because they have plenty of ebike stuff to browse through.
okmatey
10 mW
Obviously I will order what I need from a supplier in the UK, so I will have a look this evening, I will be back soon, your information is genius thanks so much,oh just before I go, what motor should be rigged up to the existing controller ?
AGS
100 W
- Joined
- Feb 13, 2023
- Messages
- 289
It’s a DC Moto controller by Lithium Battery. There are plenty of photographs showing the cable connections, especially on Ali Express. But all of the ones I have seen show white and black for the low brake cut offs. Yours are red and black so be careful with those because as stated they may be lights instead and you don’t want to short out the supply otherwise you will blow the 5v regulator. So use a multimeter to check the voltage between red and black before connecting anything to them.
They are most likely low brakes as stated on the label.
It is a 26 amp controller so:
26 amps x 36 volts = 936 watts
26 amps x 48 volts = 1248 watts
So it’s capable of running a 1000 watt motor, but be aware that UK regulations mean that a motor rated at over 250 watts is illegal and we also have a ridiculous rule about throttles only allowing 6km per hour before peddling and then motor assistance with throttle and pas has to cut out at 15.5 mph.
In reality this means that your motor should be engraved with 250 watts and the controller must be configured for it to cut out at 15.5 mph and the throttle needs to activate as said above for it to be uk compliant.
Not many self builds comply to these regulations in the UK. But KT controllers have the ability to be configured for UK compliance if you wish to do so.
The throttle rules only apply to bikes built after 1st January 2016, so for a self build you can have what is known as grandfather rights if you use an old frame, and you can have a fully acting throttle. But the law still limits you to 15.5 mph and a motor that has a 250 watt label on it. These labels are readily available on eBay.
They are most likely low brakes as stated on the label.
It is a 26 amp controller so:
26 amps x 36 volts = 936 watts
26 amps x 48 volts = 1248 watts
So it’s capable of running a 1000 watt motor, but be aware that UK regulations mean that a motor rated at over 250 watts is illegal and we also have a ridiculous rule about throttles only allowing 6km per hour before peddling and then motor assistance with throttle and pas has to cut out at 15.5 mph.
In reality this means that your motor should be engraved with 250 watts and the controller must be configured for it to cut out at 15.5 mph and the throttle needs to activate as said above for it to be uk compliant.
Not many self builds comply to these regulations in the UK. But KT controllers have the ability to be configured for UK compliance if you wish to do so.
The throttle rules only apply to bikes built after 1st January 2016, so for a self build you can have what is known as grandfather rights if you use an old frame, and you can have a fully acting throttle. But the law still limits you to 15.5 mph and a motor that has a 250 watt label on it. These labels are readily available on eBay.
Last edited:
okmatey
10 mW
AGS
100 W
- Joined
- Feb 13, 2023
- Messages
- 289
This forum will provide you with a lot of information about what is required to comply with UK law and then you can decide if you want to be compliant or not.
okmatey
10 mW
Hi guys,I've a few questions I hope you can assist with,I've been doing the mechanical side at the minute and now are ready for the electrical side.
1.The battery I have is rather battered and I really don't know what voltage it is as I haven't got a charger, is it worth tidying it up and using it for 1 controller ?
2.will 1 battery be OK for 2 motors?
3. What's the best setup for 2 motors, will a £40 controller do the job with my other controller ?
4. I've looked everywhere on the front wheel hub and can only see the numbers haven't a clue what wattage it is
Thanks guys
1.The battery I have is rather battered and I really don't know what voltage it is as I haven't got a charger, is it worth tidying it up and using it for 1 controller ?
2.will 1 battery be OK for 2 motors?
3. What's the best setup for 2 motors, will a £40 controller do the job with my other controller ?
4. I've looked everywhere on the front wheel hub and can only see the numbers haven't a clue what wattage it is
Thanks guys
1. I wouldn't use a battery pack of unknown condition or origin
2. Yes
3. Cost has no bearing on compatibility
4. Sorry, only you can see it
okmatey
10 mW
Super,so what is the compatibility issues with the controller I already have,or is there any ?
okmatey
10 mW
okmatey
10 mW
Hi chaps,I'm in the middle of my ebike restoration but I'm stuck as to what voltage the front wheel hub motor is,I've attached a picture of the writing below,
I purchased the bike 2nd hand ,it came with a dual controller 36/48v
A rear hub motor that's labeled 48v 350w
A battery that has no markings on which measures 34v.
My intentions will be to run 2 controllers eventually but in the mean time I could still purchase a battery, question is should it be a 48v battery ??
I purchased the bike 2nd hand ,it came with a dual controller 36/48v
A rear hub motor that's labeled 48v 350w
A battery that has no markings on which measures 34v.
My intentions will be to run 2 controllers eventually but in the mean time I could still purchase a battery, question is should it be a 48v battery ??
Attachments
Can the battery be charged or do you have a battery to test the motors with? I wouldn't buy anything until testing the no load speed of the two motors to determine/approximate their Kv ratings. If the rear geared motor is faster than the front direct drive, it will always be pushing the front motor, and because it's direct drive, will be loading down the rear motor continuously. If that's the case, it would be better to put a normal wheel on the front. If the direct drive is faster, then it will still be pulling the bike without contribution from the rear, but at least the rear motor can coast since it's geared, and will add less drag than with a faster rear geared motor. You should save the battery purchase, which is the most important component, until you've determined just what you're going to be powering.
okmatey
10 mW
Unfortunately I've no charger,not sure how to progress with this
docw009
1 MW
A 48V battery has 54V-40V as the typical range on the output. A 36V battery is 42V-30V. Your 34V measurement suggests you have the latter battery, as a 48V pack is supposed to shut off below 40V. If the battery is connected to the bike and still shows 34V when the controller is turned on, I would say it's a 36V battery, A 48V pack would shut off for sure.
Is that a battery mounted on top of the frame? Your picture isn't clear, but this looks like it was originally a 26" fat tire bike with a folding frame and full suspension, That would have had a controller and battery inside the frame.
Looks like you have a big direct drive motor in a suspension fork. You always have a risk of the motor twisting out of the forks, and this goes up higher if the forks are aluminum and if the motor is bigger. You might want to read up on these risks and how to lower them.
As far as the front motor, it looks like a direct drive motor and big enough able to run on either 36V or 48V. Rear motor is geared and should also handle either voltage.
Is that a battery mounted on top of the frame? Your picture isn't clear, but this looks like it was originally a 26" fat tire bike with a folding frame and full suspension, That would have had a controller and battery inside the frame.
Looks like you have a big direct drive motor in a suspension fork. You always have a risk of the motor twisting out of the forks, and this goes up higher if the forks are aluminum and if the motor is bigger. You might want to read up on these risks and how to lower them.
As far as the front motor, it looks like a direct drive motor and big enough able to run on either 36V or 48V. Rear motor is geared and should also handle either voltage.
okmatey
10 mW
I think it may be best if I ran the rear motor , with a new 48v battery, would you agree?
Chalo
100 TW
When you're working with no-name cheap generic stuff like that, you really don't have to know its identity. What matters is whether the plugs are compatible with the new components you would like to bring in. If they're not, then you have to reconcile the motor cable with the controller. Once it's testable, then you can find out the RPM/volt and assess for yourself whether the two motors can work together effectively.
okmatey
10 mW
48V 20AH BMS 40A Samsung 50E 3500mAh cells li-ion Ebike battery
48V 20AH BMS 40A Samsung 50E 3500mAh cells li-ion Ebike battery UK Stock Fast Delivery Product details: Model U009 Battery type Li ion Battery Rated Voltage 48V Rated Capacity 20Ah Battery cell Samsung 3500mAh Dimension(mm) 385*97*120 Battery weight 6 KG BMS current 40A Max.charge current 5 A...
ebikesolution.co.uk
Would this be OK?
okmatey
10 mW
The plugs on the 2 motors are the same, but was concerned it may be 36v and not 48v is there a way to check the ohms of the wiring ?
Chalo
100 TW
With an expensive ohmmeter, you could check the wire resistance. But you don't need to. The plugs are far more significant to resistance and heating, and the affected lengths of wire are short.
I used to be offended by how skinny most hub motor phase wires are, given that they are asked to carry up to 2X the current of the battery cables. But in practice they all seem to work fine even at currents well in excess of the motors' ratings.
harrisonpatm
10 kW
- Joined
- Aug 8, 2022
- Messages
- 825
Phase current is AC, transmits with fewer losses, ie, doesn't heat up the cabling as much. Which isn't to say that thicker wire wouldn't be better. But then you have a bit more difficulty running it through the axle if the wires are thicker. In addition, mass-producing manufacturers run the thinnest wire they can get away with, for cost reasons.
docw009
1 MW
Would each phase current in a BLDC be like 1/3 of the controller's max current?
harrisonpatm
10 kW
- Joined
- Aug 8, 2022
- Messages
- 825
That's assuming all controller's measure their current ratings the same way. Which they don't. Most of them have their rating based on max allowed battery current. But If I remember correctly, Kelly likes to rate their controllers based on max possible phase current, short term rather than continuous. Cuz bigger numbers.
So I guess there's not really an answer to that question, because it assumes the rating system is universal.
